. The Bell System technical journal . the same shaft com-prise the output terminal. It will be noted that voltages of oppositephase are connected to adjacent stators. Thus, with the rotors in1 L. A. Meacham, U. S. Patent No. 2,004,613. 358 BELL SYSTEM TECHNICAL JOURNAL the position shown dotted in Fig. 13 the output comes from point asince d is not coupled and b and c cancel each other. By shaping thetwo rotors so that the difference in exposure to opposite stator plates isproportional, respectively, to the sine and cosine of the angle of shaftrotation, the total current flowing from the two r
. The Bell System technical journal . the same shaft com-prise the output terminal. It will be noted that voltages of oppositephase are connected to adjacent stators. Thus, with the rotors in1 L. A. Meacham, U. S. Patent No. 2,004,613. 358 BELL SYSTEM TECHNICAL JOURNAL the position shown dotted in Fig. 13 the output comes from point asince d is not coupled and b and c cancel each other. By shaping thetwo rotors so that the difference in exposure to opposite stator plates isproportional, respectively, to the sine and cosine of the angle of shaftrotation, the total current flowing from the two rotors will be constantand of phase proportional to the shaft angle. This is illustrated bythe vector diagram in Fig. 13 in which j3 is the shaft angle and vectorsa — d and b — c are the quadrature rotor outputs proportional tosin j8 and cos /?. These phase shifters vary in output by less than ± 5 per cent as theshaft is rotated. The departure from linearity of phase shift is corre-spondingly small; , less than ± 5 Fig. 14—-The phase shifting condenser. The useful band width of this type of phase shifter is fundamentallylimited by the fact that l/coC varies with frequency while R does , this limitation does not appear in the Holmdel MUSA inwhich the percentage band width is small because the phase shiftersoperate at the intermediate frequency of 396 kilocycles. The phase shifters are connected to the steering shaft with helicalgears of multiple ratios as shown in Fig. 15. The phase shifter shaftsmay be slipped with respect to the main shaft. After they have beenaligned so that locally supplied equiphase inputs to all detectors add inphase at the point where the phase shifter outputs are combined theyare locked. This adjustment is independent of signal is made for adjusting the gain of each of the six phase shiftercircuits so that the differences in transmission-line loss may be com- A MULTIPLE UNIT STEERABLE ANTENNA 359 pensat
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
